Remarkable MnO2 structure-dependent H2O promoting effect in HCHO oxidation at room temperature.
Remarkable MnO2 structure-dependent H2O promoting effect in HCHO oxidation at room temperature.
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DOI：
10.1016/j.jhazmat.2021.125542
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发表时间：
2021-02
影响因子：
13.6
通讯作者：
Chun-yan Ma;Shumei Sun;Hao Lu;Z. Hao;Chenggong Yang;Bin Wang;Cheng Chen;Maoyong Song
中科院分区：
文献类型：
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作者：
Chun-yan Ma;Shumei Sun;Hao Lu;Z. Hao;Chenggong Yang;Bin Wang;Cheng Chen;Maoyong Song
H2O 对于确定 HCHO 氧化金属氧化物催化剂的活性和稳定性通常至关重要；然而，合成具有超强耐水性的金属氧化物催化剂仍然是一个挑战。在此，我们合成了沿 MnO6 八面体层延伸的 Mn-O-Mn 的白铁矿型 MnO2 催化剂，这促进了缔合吸附的 H2O 的利用。室温下甲醛氧化活性和稳定性在潮湿空气中增强。使用漫反射红外傅里叶变换 (DRIRFT) 光谱来表征 H2O 吸附和中间物质。缔合吸附的 H2O 促进甲醛通过甲酸中间体氧化为 CO2。由于甲酸的生成，MnO2的使用寿命得以延长。当甲酸积累并形成甲酸和碳酸氢盐时，MnO2 逐渐失活。这项研究为开发用于潮湿空气中甲醛氧化的高效 MnO2 催化剂提供了重要见解，并且所开发的 MnO2 催化剂是实际消除甲醛的有希望的候选者。
H2O is often critical in determining the activity and stability of metal oxide catalysts for HCHO oxidation; however, synthesis of metal oxide catalysts with super resistance to H2O remains a challenging. Herein, we synthesized Akhtenskite-type MnO2catalyst with Mn–O–Mn stretching along MnO6octahedra layers, which promotes the utilization of the associatively adsorbed H2O. The activity and stability of formaldehyde oxidation at room temperature enhanced in humid air. Diffuse-reflectance infrared Fourier transform (DRIRFT) spectroscopy was used to characterize the H2O adsorption and intermediate species. The associatively adsorbed H2O promotes the oxidation of formaldehyde to CO2via the formic acid intermediate. The service life of MnO2is prolonged due to formic acid generation. MnO2gradually deactivates when formic acid accumulates and forms formate and hydrogen carbonate species. This study provides significant insights into the development of a high-efficiency MnO2catalyst for formaldehyde oxidation in humid air, and the developed MnO2catalyst is a promising candidate for application in practical formaldehyde elimination.